Hi all! My variant

class OrderType(StrEnum):
ONLINE = "online"
IN_STORE = "in-store"

process_order(in_store_order)


Watching the challenges and reading the solutions people came up with in the comments has been fascinating and inspiring. A suggestion for the site is to support markdown and provide syntax highlighting in the code block.

Well, I didn't quite follow directions. I did a combination between reducing repetition and changing the scope of the functions.

from dataclasses import dataclass
from decimal import Decimal
from enum import StrEnum
from typing import Iterable

class OrderType(StrEnum):
ONLINE = "online"
IN_STORE = "in store"

@dataclass
class Item:
name: str
price: Decimal

@dataclass
class Email:
body: str
subject: str
recipient: str
sender: str

@staticmethod
def generate_confirmation_email(order: "Order") -> "Email":
return Email(
body=f"Thank you for your order! Your order #{order.order_id} has been confirmed.",
subject="Order Confirmation",
recipient=order.customer_email,
sender="sales@webshop.com",
)

@staticmethod
def generate_shipping_notification(order: "Order") -> "Email":
return Email(
body=f"Good news! Your order #{order.order_id} has been shipped and is on its way.",
subject="Order Shipped",
recipient=order.customer_email,
sender="sales@webshop.com",
)

@dataclass
class Order:
order_id: int
order_type: OrderType
customer_email: str

def __init__(self, order_id: int, order_type: OrderType, customer_email: str):
self.order_id = order_id
self.order_type = order_type
self.customer_email = customer_email

def process(self) -> None:
if self.order_type == OrderType.ONLINE:
print("Processing online order...")
print(Email.generate_confirmation_email(self))
print("Shipping the order...")
print(Email.generate_shipping_notification(self))
elif self.order_type == OrderType.IN_STORE:
print("Processing in-store order...")
print(Email.generate_confirmation_email(self))
print("Order ready for pickup.")
else:
raise ValueError("Invalid order type.")
print("Order processed successfully.")

def calculate_price(items: Iterable[Item], discount: Decimal = Decimal("0")) -> Decimal:
total_price = Decimal(sum(item.price for item in items))
discounted_price = total_price - (total_price * discount)
return discounted_price

def main() -> None:
items = [
Item(name="T-Shirt", price=Decimal("19.99")),
Item(name="Jeans", price=Decimal("49.99")),
Item(name="Shoes", price=Decimal("79.99")),
]

online_order = Order(
order_id=123, order_type=OrderType.ONLINE, customer_email="sarah@gmail.com"
)

total_price = calculate_price(items, Decimal("0.0"))
print("Total price:", total_price)

discounted_price = calculate_price(items, Decimal("0.1"))
print("Discounted price:", discounted_price)

online_order.process()

in_store_order = Order(
order_id=456, order_type=OrderType.IN_STORE, customer_email="john@gmail.com"
)

in_store_order.process()

if __name__ == "__main__":
main()

Why method that sending emails should know anything about order? maybe it's better to create just function with id,body, subject, recipient parameters. also we could re use it for later for example invoice confirmation.

Here is my solution:

from decimal import Decimal
from dataclasses import dataclass
from enum import StrEnum
from typing import Iterable

class OrderType(StrEnum):
ONLINE = "online"
IN_STORE = "in store"

class NotificationType(StrEnum):
CONFIRMATION = "confirmation"
SHIPPING = "shipping"

@dataclass
class Item:
name: str
price: Decimal

@dataclass
class Order:
id: int
type: OrderType
customer_email: str

@dataclass
class Email:
body: str
subject: str
recipient: str
sender: str

def calculate_prices(items: Iterable[Item], discount: Decimal | None) -> dict[str, Decimal]:
list_prices: dict[str, Decimal] = {}
total_price = Decimal(sum(item.price for item in items))
list_prices["total_price"] = total_price
if discount is not None:
discounted_price = total_price - (total_price * discount)
list_prices["discounted_price"] = discounted_price
return list_prices

def generate_order_email_notifications(order: Order, notification: NotificationType) -> Email:
if notification == NotificationType.CONFIRMATION:
body = f"Thank you for your order! Your order #{order.id} has been confirmed."
subject = "Order Confirmation"
elif notification == NotificationType.SHIPPING:
body = f"Good news! Your order #{order.id} has been shipped and is on its way."
subject = "Order Shipped"
return Email(
body = body,
subject = subject,
recipient = order.customer_email,
sender = "sales@webshop.com",
)

def process_orders(order: Order) -> None:
print(f"Processing {order.type} order...")
print(generate_order_email_notifications(order, NotificationType.CONFIRMATION))
if order.type == OrderType.ONLINE:
print("Shipping the order...")
print(generate_order_email_notifications(order, NotificationType.SHIPPING))
elif order.type == OrderType.IN_STORE:
print("Order ready for pickup.")
print("Order processed successfully.")

def main() -> None:
items = [
Item(name="T-Shirt", price=Decimal("19.99")),
Item(name="Jeans", price=Decimal("49.99")),
Item(name="Shoes", price=Decimal("79.99")),
]

online_order = Order(
id=123, type=OrderType.ONLINE, customer_email="sarah@gmail.com"
)

total_price = calculate_prices(items, Decimal("0.1"))
print("Total price:", total_price["total_price"])
print("Discounted price:", total_price["discounted_price"])

process_orders(online_order)

in_store_order = Order(
id=456, type=OrderType.IN_STORE, customer_email="john@gmail.com"
)

process_orders(in_store_order)

if __name__ == "__main__":
main()